In one well-known form of lighting fixture, a troffer is recessed in a ceiling and provided with a lowermost door or lens through which the light from the fluorescent bulbs installed therein passes in illuminating the space below.
It is conventional to provide in the door or lens frame, an inwardly opening peripheral channel for receiving the peripheral edges of the louver or lens. Heretofore, a large number of lens arrangements have been required for use with the different troffer configurations and utilizing the different louver cell configurations.
It has been conventional to provide louvers cells in either small opening form or large opening form. Thus, illustratively, a conventional configuration for a louver having small opening cells is one wherein the cells have a square cross section at the lower portion thereof of approximately 0.585" per side. In another form of such louvers utilizing relatively large open cells, the cells have a square cross section at the bottom portion thereof of approximately 1.450" per side.
It has been conventional to provide louvers with the edge cells thereof received in the channels of the doors or frames. Alternatively, flanged adapters may be provided to be mounted on the peripheral edges of the louver and define flange means for reception in the channels of the mounting structure.
In one known construction, the louver has been provided with an integral molded flange.